1. Field of the Invention
The present invention relates to a spacer-less type pipe joint and a packing ring used for the same, and in particular, to a spacer-less pipe joint made of metal or resin and used for a water pipe or the like and a packing ring used for the same.
2. Description of the Related Art
FIG. 10 shows a structural example of this type of conventional pipe joint made of metal or resin and used for a water pipe or the like. The pipe joint is used to joint end portions of jointed pipes 61, 61, which are made of metal or resin and oppose to each other on an axis in such a way that expansion and flexibility shown by arrows are maintained and thus a liquid does not leak. That is, the pipe joint comprises a joint main body 62 and a pair of press rings 63, 63, and the press rings are clamped by securing tools 64 such as bolts. The joint main body 62 has flange-shaped protruding portions 62a, 62a opposing to each other. A cylindrical portion 62b is provided between these protruding portions 62a, 62a so as to be integral therewith. A receiving opening portion 62c, which is widened outward toward an end portion is provided at an inner periphery of the protruding portion 62a. The press ring 63 also has a flange-shaped protruding portion 63a. The joint main body 62 is disposed at an outer periphery between the jointed pipes 61, 61 with a peripheral clearance formed therebetween, the press rings 63, 63 are disposed at opposite ends of the joint main body and clamped by the securing tools 64. By clamping with the securing tool 64, a rubber packing ring 65 disposed between the joint main body 62 and each of the press rings 63 is pressed by a distal end portion of the press ring 63 to be coupled to the receiving opening portion 62c, press-contacted to an outer peripheral surface of the jointed pipe 61, so that the jointed pipes 61, 61 are jointed together.
In a case of the above-described conventional pipe joint, required components are transported to a field in a state of disassembled. The components are then assembled and applied. Among conventional other pipe joints, a pipe joint which is assembled in advance may be used in order to even further improve workability in the field. Namely, an annular spacer 66 shown in FIG. 11 is used. As shown in FIG. 12(a), an engaging concave portion 67a of a rubber packing ring 67 and an engaging convex portion 66a of the spacer 66 are fitted so as to be assembled together. A distal end portion of the rubber packing ring 67 is entered into a receiving opening portion 68c of a joint main body 68, and a press ring 69 is clamped by a securing tool (not shown) until a positioning protrusion 66b of the spacer 66 abuts and fits on a corner of an opening edge of the receiving opening portion 68c. In this way, temporary assembling is performed. In the temporarily assembled pipe joint, the rubber packing ring 67 is positioned (aligned) by the positioning protrusion 66b of the spacer 66 in an axial direction as well as a radial direction.
The pipe joint temporarily assembled by the above-described manner is transported to a field. As shown in FIG. 12(b), the jointed pipe 61 is then inserted. Subsequently, further clamping is performed by the securing tool (not shown) and the positioning protrusion 66b of the spacer is bent and rolled. Moreover, as shown in FIG. 12(c), the rubber packing ring 67 is coupled to the receiving opening portion 68c in a wedge-shaped manner and press-contacts the outer peripheral surface of the jointed pipe 61. In this way, operation in the field is rapidly completed.
In a case of the above-described conventional pipe joint with a spacer, however, it is not easy to position the rubber packing ring 65, 67 in radial and axial directions. Further, there arises a problem in that the positioning protrusion 66b of the spacer 66 may be broken during transport and a temporarily assembled state of the pipe joint is broken.
In accordance with the rubber packing ring 65 shown in FIG. 10, because a reference for radial and axial positioning is not provided, it is not easy to securely position the rubber packing ring 65. In accordance with the rubber packing ring 67 shown in FIG. 12, the engaging concave portion 67a of the rubber packing ring 67 is fitted into the engaging convex portion 66a of the spacer 66 and assembled thereto. The press ring 69 is then clamped by the securing tool (not shown) until the positioning protrusion 66b of the spacer 66 abuts and fits on the corner of the opening edge of the receiving opening portion 68. This is burdensome operation and is not easy.
Further, if the temporarily assembled state is broken and the radial and axial position of the rubber packing ring 67 is also shifted, the press ring 69 is dislocated and abuts on the rubber packing ring 67, and the rubber packing ring 67 is damaged. Alternatively, in a state where the jointed pipe 61 is not inserted, the rubber packing ring 67 moves further deeply into the receiving opening portion 68c and thus a diameter of the rubber packing ring 67 is significantly reduced, so that the rubber packing ring 67 becomes defective. At this case, the defective rubber packing ring 67 and the spacer 66 must be removed and a new rubber packing ring 67 and a new spacer 66 must be mounted again. As a result, an operation in the field becomes troublesome.
An object of the present invention is, in light of the above-described problems of the related art, to provide a spacer-less pipe joint wherein the radial and axial positioning of a packing ring is easily performed and a temporarily assembled state is difficult to break, and to provide a packing ring used for the same.
The aforementioned object is accomplished by the present inventions. Namely, a spacer-less type pipe joint comprising:
a press ring which has a protruding portion at its outer periphery and is fitted to an outer periphery of one end side of a jointed pipe; and
a joint main body which includes i) a protruding portion opposing the protruding portion of the press ring at a side opposing the press ring, and ii) a receiving opening portion which is widened toward the press ring at an inner periphery of the protruding portion of the joint main body so as to be fitted to the outer periphery of the jointed pipe with a peripheral clearance being formed therebetween, characterized in that a securing tool can move the press ring in a direction toward the joint main body; and
a packing ring which is provided between the joint main body and the jointed pipe and fitted into the receiving opening portion by its elastic deformation caused by being directly pressed by the press ring moved by operation of the securing tool,
wherein the packing ring is formed of a distal end portion at a side of the receiving opening portion and a basal portion at a side of the press ring, a diameter of an outer periphery of the distal end portion is substantially the same as an inner diameter of the receiving opening portion such that the distal end portion is temporarily fixed to an entrance of the receiving opening portion, and a diameter of an outer periphery of the basal portion is larger than the outer diameter of the distal end portion only at a portion connecting to the distal end portion, so that a stopper abutting on a peripheral edge outer surface of the receiving opening portion is formed by the outer periphery of the basal portion.
Due to such structure, the distal end portion of the packing ring is temporarily fixed to an entrance of the receiving opening portion such that the stopper of the basal portion of the packing ring abuts on a peripheral edge outer surface of the receiving opening portion of the joint main body. The press ring which is moved by operation of the securing tool abuts on the press ring side end surface of the basal portion of the packing ring. In this way, temporary assembling is performed. Subsequently, in the state of the jointed pipe inserted into the temporarily assembled pipe joint, the press ring is moved by operation of the securing tool. The packing ring including the stopper is elastically deformed by direct press by the press ring being moved so as to enter further into the receiving opening portion and is closely coupled to the receiving opening portion in a wedge-shaped manner. The packing ring also press-contacts the outer peripheral surface of the jointed pipe, the packing ring is fitted and the jointed pipes are jointed together. A pipe to be jointed to the jointed pipe may be used instead of the joint main body.
In accordance with the spacer-less type pipe joint, by merely temporarily fixing the distal end portion of the packing ring to the entrance of the receiving opening portion such that the stopper of the basal portion of the packing ring abuts on the peripheral edge outer surface of the pipe or the joint main body, the packing ring is radially positioned by the distal end portion temporarily fixed to the entrance of the receiving opening portion without requiring the operation of assembling the packing ring to a spacer. Further, the packing ring is axially positioned by the stopper abutting on the peripheral edge outer surface of the receiving opening portion of the pipe or the joint main body. Thus, the radial and axial positioning of the packing ring is easy, and moreover, as the spacer is not used, it may not occur that a temporarily assembled state is broken caused by breakage in the spacer so that the temporarily assembled state of the pipe joint is hardly broken.
A concave portion is preferably formed at the side of the stopper of the basal portion of the packing ring on which the receiving opening portion abuts.
Due to the above structure, when the stopper of the packing ring is elastically deformed by being directly pressed by the press ring so that the packing ring enters into the receiving opening portion of the pipe or the joint main body, the distal end side of the stopper is easily deformed, so that the stopper can smoothly enter the receiving opening portion of the pipe or the joint main body.
Moreover, the stopper of the basal portion of the packing ring preferably has hardness HA of 90xc2x0xc2x15xc2x0.
Due to this structure, as the stopper of the basal portion of the packing ring has hardness HA of 90xc2x0xc2x15xc2x0, the stopper combines appropriate hardness and elastic deformability. As the stopper of the basal portion of the packing ring has appropriate hardness and sufficiently functions as a stopper, a temporarily assembled state is difficult to break. Additionally, the stopper exhibits sufficient elastic deformability, and is easily deformed when the packing ring is entered into the receiving opening portion of the pipe or the joint main body.
In addition, at the basal portion of the packing ring, an outer peripheral side fin portion which protrudes toward the press ring side is formed along a periphery of the press ring side outer peripheral end edge, and a diameter of an inner periphery of the outer peripheral side fin portion is preferably substantially the same as an outer diameter of the distal end portion of the press ring.
Due to this structure, when the press ring abuts on the press ring side end surface of the basal portion of the packing ring, the distal end portion of the press ring is fitted within the outer peripheral side fin portion at a side of the packing ring having a diameter which is substantially the same as the outer diameter of the distal end portion of the press ring. As the distal end portion of the press ring which abuts on the press ring side end surface of the basal portion of the packing ring is securely fitted within the outer peripheral side fin portion, the radial positioning of the press ring and the packing ring is automatically performed, which is convenient.
Furthermore, at the basal portion of the packing ring, an inner peripheral side fin portion which protrudes toward the press ring side is formed along a periphery of the press ring side inner peripheral end edge, and an outer diameter of the inner peripheral side fin portion is preferably substantially the same as the inner diameter of the distal end portion of the press ring.
Due to this structure, when the press ring abuts on the press ring side end surface of the basal portion of the packing ring, the distal end portion of the press ring fits an outside of the inner periphery side fin portion at a side of the packing ring having a diameter which is substantially the same as the inner diameter of the distal end portion of the press ring. As the distal end portion of the press ring abutting on the press ring side end surface of the basal portion of the packing ring is securely fitted to the outside the inner peripheral side fin portion, the press ring and the packing ring are automatically positioned in a radial direction.
Furthermore, the distal end portion of the packing ring is preferably a soft portion, and the basal portion thereof is preferably a hard portion.
Due to this structure, when the distal end portion of the press ring abuts on the hard portion which is the basal portion of the packing ring, the soft portion, which is the distal end portion of the packing ring, is closely coupled to the receiving opening portion in a wedge-shaped manner and press-contacts the outer peripheral surface of the jointed pipe. As the basal portion of the packing ring abutting on the distal end portion of the press ring is the hard portion, pressing by the press ring is securely transmitted to the packing ring. Further, the distal end portion of the packing ring, which is closely coupled to the receiving opening portion in a wedge-shaped manner and press-contacts the outer peripheral surface of the jointed pipe, is the soft portion, so that sealing property is improved.
An inner periphery of the packing ring in a natural state is preferably larger than the outer periphery of the jointed pipe.
In accordance with the spacer-less type pipe joint with the above-described structure, when a unit of the joint main body, the packing ring and the press ring assembled in advance is transported to an applied field and the like and then applied, the operation for assembling the jointed pipe to the unit is easy, and the packing ring is press-fitted into the receiving opening portion without excess resistance, which is convenient.
A characteristic structure of packing ring according to the present invention can be used for the spacer-less type pipe joint according to an embodiment of the present invention and can comprise a distal end portion which is soft, and a basal portion which is hard. An outer diameter of the distal end portion is substantially the same as the inner diameter of the receiving opening portion such that the distal end portion can be temporarily fixed to an entrance of the receiving opening portion of the joint main body structuring the spacer-less type pipe joint, and an outer periphery of the basal portion has larger diameter than the outer diameter of that distal end portion only at a portion connecting to the distal end portion, so that a stopper abutting on a peripheral edge outer surface of the receiving opening portion is formed.
Due to this structure, when the packing ring is inserted into the spacer-less pipe joint, the packing ring can be easily positioned in radial and axial directions. Further, the packing ring used for the spacer-less pipe joint whose temporarily assembled state is difficult to break can be provided.
When the stopper of the basal portion has a concave portion at the side abutting on the peripheral edge outer surface of the receiving opening portion described-above, in case of being entered into the receiving opening portion by the press ring, the stopper can smoothly enter the receiving opening portion of the pipe or the joint main body, which is convenient. Further, a fin portion which protrudes toward the press ring side of the basel portion of the packing ring is formed and the distal end portion of the press ring is fitted within the fin portion. Thus, it is convenient since the positioning becomes easy.